Plenty of Amazon customers have migrated from paper books to the Kindle in recent years, but what good are all those mountains of physical books on your shelves doing you then? When Amazon’s new Matchbook service goes live, they could be worth their weight in ebooks. Amazon will reach back into your account and offer discounts on the Kindle edition of participating physical books you’ve previously bought. You’ll be able to get the Kindle books for $2.99, $1.99, $0.99, or free, depending on the title.

Kindle Matchbook is going to offer discounts on supported books that were bought at any point in the history of Amazon. If you bought a paperback edition of something in 1995, you will be eligible for the discounted Kindle price, even if the physical book has long since been lost or sold. However, the purchase needs to have been made on the same account you have connected to your Kindle.

There are currently about 10,000 books enrolled in Kindle Matchbook from authors like Neil Gaiman, Ray Bradbury, and Neal Stephenson. Publishers will have to get on-board before buyers get any discounts for the Kindle books. Amazon is seeking additional partnerships, and it shouldn’t have too much trouble getting them. Publishers live to sell the same thing multiple times, even if it’s at a discount.

Amazon will make it easy to see what books you have that are supported by Kindle Matchbook. You’ll be able to look up your entire print book history and see everything compatible with Matchbook. The service is set to launch in October, but Amazon isn’t saying what the pricing distribution will be. The free Kindle editions will probably be much less common than the $2.99 ebook upgrades, though.